<template>
  <div
    class="side-nav"
    :class="{ 'is-fade': isFade }"
    :style="navStyle"
    @mouseenter="isFade = false"
  >
    <ul>
      <!-- <li class="nav-item sponsors">
        <a>{{ lang === 'zh-CN' ? '赞助者名单' : 'Sponsors' }}</a>
        <ul class="pure-menu-list sub-nav">
          <li class="nav-item">
            <a class="sponsor" href="./sponsors" target="_blank">
              <img src="~examples/assets/images/duohui.svg" alt="duohui">
            </a>
          </li>
        </ul>
      </li> -->
      <li
        v-for="(item, keyy) in data"
        :key="keyy"
        class="nav-item"
      >
        <a v-if="!item.path && !item.href" @click="expandMenu">{{ item.name }}</a>
        <a v-if="item.href" :href="item.href" target="_blank">{{ item.name }}</a>
        <router-link
          v-if="item.path"
          active-class="active"
          :to="base + item.path"
          exact
          v-text="item.title || item.name"
        />
        <ul v-if="item.children" class="pure-menu-list sub-nav">
          <li
            v-for="(navItem, key) in item.children"
            :key="key"
            class="nav-item"
          >
            <router-link
              class=""
              active-class="active"
              :to="base + navItem.path"
              exact
              v-text="navItem.title || navItem.name"
            />
          </li>
        </ul>
        <template v-if="item.groups">
          <div
            v-for="(group, key) in item.groups"
            :key="key"
            class="nav-group"
          >
            <div class="nav-group__title" @click="expandMenu">{{ group.groupName }}</div>
            <ul class="pure-menu-list">
              <li
                v-for="(navItem, keey) in group.list"
                v-show="!navItem.disabled"
                :key="keey"
                class="nav-item"
              >
                <router-link
                  active-class="active"
                  :to="base + navItem.path"
                  exact
                  v-text="navItem.title"
                />
              </li>
            </ul>
          </div>
        </template>
      </li>
    </ul>
    <!--<div id="code-sponsor-widget"></div>-->
  </div>
</template>
<script>
import bus from '../bus'
import compoLang from '../i18n/component.json'

export default {
  props: {
    data: {
      type: Array,
      default: () => ([]),
    },
    base: {
      type: String,
      default: '',
    },
  },
  data() {
    return {
      highlights: [],
      navState: [],
      isSmallScreen: false,
      isFade: false,
    }
  },
  computed: {
    navStyle() {
      const style = {}
      if (this.isSmallScreen) {
        style.paddingBottom = '60px'
      }
      style.opacity = this.isFade ? '0.5' : '1'
      return style
    },
    lang() {
      return this.$route.meta.lang
    },
    langConfig() {
      return compoLang.filter(config => config.lang === this.lang)[0]['nav']
    },
  },
  watch: {
    '$route.path'() {
      this.handlePathChange()
    },
    isFade(val) {
      bus.$emit('nav-fade', val)
    },
  },
  created() {
    bus.$on('fade-nav', () => {
      this.isFade = true
    })
  },
  mounted() {
    this.handleResize()
    window.addEventListener('resize', this.handleResize)
  },
  beforeUnmount() {
    window.removeEventListener('resize', this.handleResize)
  },
  methods: {
    handleResize() {
      this.isSmallScreen = document.documentElement.clientWidth < 768
      this.handlePathChange()
    },
    handlePathChange() {
      if (!this.isSmallScreen) {
        this.expandAllMenu()
        return
      }
      this.$nextTick(() => {
        this.hideAllMenu()
        let activeAnchor = this.$el.querySelector('a.active')
        let ul = activeAnchor.parentNode
        while (ul.tagName !== 'UL') {
          ul = ul.parentNode
        }
        ul.style.height = 'auto'
      })
    },
    hideAllMenu() {
      [].forEach.call(this.$el.querySelectorAll('.pure-menu-list'), ul => {
        ul.style.height = '0'
      })
    },
    expandAllMenu() {
      [].forEach.call(this.$el.querySelectorAll('.pure-menu-list'), ul => {
        ul.style.height = 'auto'
      })
    },
    expandMenu(event) {
      if (!this.isSmallScreen) return
      let target = event.currentTarget
      if (!target.nextElementSibling || target.nextElementSibling.tagName !== 'UL') return
      this.hideAllMenu()
      event.currentTarget.nextElementSibling.style.height = 'auto'
    },
  },
}
</script>
<style lang="scss" scoped>
  .side-nav {
    width: 100%;
    box-sizing: border-box;
    padding-right: 30px;
    transition: opacity .3s;
    &.is-fade {
      transition: opacity 3s;
    }

    li {
      list-style: none;
    }

    ul {
      padding: 0;
      margin: 0;
      overflow: hidden;
    }

    > ul > .nav-item > a {
      margin-top: 15px;
    }

    > ul > .nav-item:nth-child(-n + 4) > a {
      margin-top: 0;
    }

    .nav-item {
      a {
        font-size: 16px;
        color: #333;
        line-height: 40px;
        height: 40px;
        margin: 0;
        padding: 0;
        text-decoration: none;
        display: block;
        position: relative;
        transition: .15s ease-out;
        font-weight: bold;

        &.active {
          color: #409EFF;
        }
      }

      .nav-item {
        a {
          display: block;
          height: 40px;
          color: #444;
          line-height: 40px;
          font-size: 14px;
          overflow: hidden;
          white-space: nowrap;
          text-overflow: ellipsis;
          font-weight: normal;

          &:hover,
          &.active {
            color: #409EFF;
          }
        }
      }

      &.sponsors {
        & > .sub-nav {
          margin-top: -10px;
        }

        & > a {
          color: #777;
          font-weight: 300;
          font-size: 14px;
        }

        .nav-item {
          display: inline-block;

          a {
            height: auto;
            display: inline-block;
            vertical-align: middle;
            margin: 8px 20px 4px 0;

            img {
              width: 36px;
            }
          }
        }
      }
    }

    .nav-group__title {
      font-size: 12px;
      color: #999;
      line-height: 26px;
      margin-top: 15px;
    }

    #code-sponsor-widget {
      margin: 0 0 0 -20px;
    }
  }
  .nav-dropdown-list {
    width: 120px;
    margin-top: -8px;
    li {
      font-size: 14px;
    }
  }
</style>
